Radiograph recording apparatus

ABSTRACT

In a radiographic examination apparatus comprising an X-ray generator and an image multiplier tube which produces an image in response to X-rays received from an object being examined an apparatus for obtaining a single continuous radiographic record of an object examined, wherein said image multiplier tube image is constantly scanned by a television camera, video-signals produced by said television camera in response to said image multiplier tube image scanned are supplied to a video signals recording means, and output produced by said video signals recording means in response to said television camera video signals is applied to the surface of a recording material that is moved relative to and perpendicularly or approximately perpendicularly to the direction of the scanning line of said video signals recording means, thereby to obtain a continuous print out of a radiographic image of the object over which the television camera is moving.

United States Patent [111 3,855,471

Ikegami Dec. 17, 1974 RADIOGRAPH RECORDING APPARATUS Primary Examiner-Archie R. Borchelt Assistant Examiner-D. C. Nelms 1 k [75] Inventor Yoshlzo lkegaml Amagasa I Japan Attorney, Agent, or Fzrm-Crarg & Antonelll [73] Assignee: Konan Camera Research Institute,

Nishinomiya, Hyogo, Japan [57] ABSTRACT [22] Filed: Apr. 20, 1973 ln a radiographic examination apparatus comprising [211 App]. No; 352,990 an X-ray generator and an image multiplier tube which produces an image in response to X-rays received from an object being examined an apparatus [52] US. Cl. 250/320, 250/323 for obtaining a single-continuous radiographic record [51] Int. Cl. G01n 21/34 of an object examined, wherein said image multiplier [58] Field of Search 250/320, 321, 322, 323 tube image is constantly scanned by a television camera, video-signals produced by said television camera [56] References Cited in response to said image multiplier tube image UNITED STATES PATENTS scanned are supplied to a video signals recording 2 680 I99 6/1954 Abel 250,323 means, and output produced by said video signals re- 2'857523 10H958 250522 cording means in response to said television camera 2374300 2/1959 vanAlphemu 250/320 video signals is applied to the surface of a recording 2,922,885 l/1960 Tittle 250/321 material that is moved relative to and perpendicularly 3,126,480 3/l964 Bouwers 250/322 or approximately perpendicularly to the direction of 3, 12/1968 e a /322 the scanning line of said video signals recording 3-499-146 3/1970 Richards 250/320 means, thereby to obtain a continuous print out of a g radiographic image of the object over which the teleergs e i. 3,633,478 1/1972 lshimatsu 250/320 camera movmg' 8 Claims, 2 Drawing Figures RADIOGRAPH RECORDING APPARATUS The present invention relates to a means for radiographic examination. More particularly the invention relates to a radiographic examination apparatus whereby it is possible to obtain an immediateX-ray photograph of an object radiographically examined.

As a means for non-destructive inspection of materials it is common practice to employ a radiographic examination equipment. Such equipment is widely used for the inspection of metal castings and welded prod ucts and consists essentially of producing X-ray in an object, or position of an object, to be inspected, by means of an X-ray generator, that is an assembly comprising such devices as a high-voltage transformer, rectifier, X-ray tube, and controllers for the generation of X-rays, applying the X-rays that have passed through the object being inspected to an image intensifying tube to obtain an image on a fluorescent screen thereof, photographing the image on the fluorescent screen by means of a special camera and film, developing the film andv obtaining a print of the photograph, which can then be examined to determined whether there are any faults in the object inspected.

Such conventional radiographic examination means have certain inherent disadvantages, which concern cost and manipulation. The disadvantage with regard to cost is that since images obtained on the fluorescent screen of an image intensifying tube are dark, ordinary cameras and film are unsuitable for photographing such images, and it is necessary to use an expensive,

special camera and special film. Another disadvantage associated with conventional equipment is that since the area covered by an image obtained on a fluorescent sheet is very narrow, when it is desired to inspect, for example, the whole of a weld joining the long sides of two pieces of metal, a single photograph is insufficient, and it is necessary to produces a series of radiographs, that is, one for each succeeding portion of the weld; care must be taken that these radiographs overlap slightly, to ensure that no part of the weld is missed, and also the individual radiographs must be identified, so that it may be known what portion of the weld they represent. Thus, while no doubt very accurate, inspection of materials using conventional radiographic equipment can be complex and demanding of both staff time.

It is accordingly an object of the present invention provide an apparatus whereby it is possible to obtain a continuous radiographic image of an object to be inspected, whatever the length of the object.

It is another object of the invention provide an apparatus whereby it is possible to obtain such a continuous image in a short time and in a single operation.

It is a further object of the invention to provide an apparatus for accomplishing the above-stated objects using only conventional and inexpensive equipment.

In accomplishing these and other objects there has been provided in accordance with the present invention an assembly that comprises a wheeled platform carrying an X-ray generator and a television camera that effects continuous scanning of one line of the fluorescent screen of an image multiplier tube. The camera and image multiplier tube are carried on top of the platform and the X-ray generator is carried on an underslung arm or shelf that is part of a bracket-like projection from one side of the top of the platform, and the platform is moved along an object to be radiographically inspected with the object to be inspected lying between the X-ray generator supported beneath the platform and the television camera and image multiplier tube supported on top of the platform. Output from the image multiplier tube on to its fluorescent screen is scanned by the television camera and video signals from the television camera are supplied to a photofibre memory tube, or similar means, whose scanning is synchronized with that of the television, and the photofibre memory tube supplies corresponding signals to the surface of a recording material that is moved past the memory tubein a direction that is approximately perpendicular to that'of the memory tube scan. In this manner there is obtained a continuous print-out of a radiographic image of the object over which the television camera is moving.

For a better understanding of the invention, one preferred embodiment thereof will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a schematic block diagram showing the main elements in a radiograph recording apparatus in one embodimentof the present invention, and

FIG. 2 is an explanatory sectional view showing the moving radiographic elements in the embodiment of FIG. 1.

Through out the description of the drawings, like parts are designated by like reference numerals.

The apparatus of the invention, as illustrated in FIG. 1, comprises essentially an X-ray generator 4, an image multiplier tube 5, a television camera tube 6, a photofibre memory tube 7, a deflection circuit 13, and a supply of photo-recording'paper 8. The X-ray generator 4 and the image multiplier tube 5 are respectively designed as conventional types, and the former generates X-rays at its front plate 4a toward the latter which in response produces a photo-image of an object existing between both on its fluorescent screen 5a of which area corresponds to that of the front plate of the former. The camera tube 6 is a linear scanner type of conventional design which has a scanning'range at least equal to the length of the line covered by an object on the fluorescent screen of the image multiplier tube at a constant point of the fluorescent screen which is desired to obtain a record of the object. However, if all of the object, X-ray generator 4 and image multiplier tube 5 are, for example, fixed'at a certain position, the camera tube 6 is designed to move in such a manner that the line scanned by the camera tube 6 traverses the'fluorescent screen of the image multiplier tube 5 from its one end to its other end, so that the camera tube 6 can scan all objects appeared within the fluorescent screen 5a of the image multiplier tube 5. Also, if the position of the object to be inspected relative to both the X-ray generator 4 and image multiplier tube 5 is changed, either by change of the position of said object or said X-ray gen erator 4 and image multiplier tube 5 or by placing a moving optical means (not shown in FIG. 1) between said object, said X-ray generator and said image multiplier tube, the camera tube 6 is arranged to the flourescent screen 5a of the image multiplier tube 5 in such a manner that the line scanned by the camera tube 6 is placed in a direction perpendicular to the changing direction of said object or said X-ray generator 4 and image multiplier tube 5, so that said line scanned by the camera tube 6 is moved step by step along the changing direction of said object or said x-ray generator 4 and image multiplier tube in accordance with the movement of said object or said X-ray generator 4 and image multiplier tube 5. Accordingly, when the X-ray generator 4 and image multiplier tube 5 are moved along the fixed object, the camera tube 6 is fixed in connection with the X-ray generator 4 and image multiplier tube 5 and constantly scans on a line within the fluorescent screen 5a of the image multiplier tube 5, said line being in the direction perpendicular to the moving direction of all the X-ray generator 4, image multiplier tube 5 and camera tube 6 relative to the object, so that the camera tube 6 can successively scan the successive portions of the object in accordance with the movement of all the X-ray generator 14 image multiplier tube 5 and camera tube 6. The camera tube 6 is associated with a deflection coil 60 which is supplied a saw-tooth wave based on a clock pulse of, for example, lOKHz from the deflection circuit 13; in this manner, although the sweep of the camera tube 6 electron beam is only linear, the breadth of sweep thereof, that is the scanning line width can be adjusted to any value desired by varying the saw-tooth wave controlling the camera tube deflection coil 6a. The video signal output of the camera tube 6 is supplied as input to the photo-fibre memory tube 7 which has a photo-fibre plate 7a positioned at its output end and which produces an electron beam which sweeps the photo-fibre platelinearly and lengthwise. The photo-flbre memory tube 7 is also equipped with a deflection coil 7b on which is impressed the sawtooth wave output from the deflection circuit 13. Accordingly, since the deflection coils 6a, 7b of both the camera tube 6 and the photo-fibre memory tube 7 simultaneously have impressed the same saw-tooth wave, the sweep of the electron beam of the photo-fibre memory tube 7 is synchronized with that of the camera tube 6 electron beam. The photosensitive recording paper 8 is moved by and approximately parallel to the long axis of the photo-fibre plate 70 at the end of the photo-fibre memory tube 7 as shown in the direction of an arrow A. Commercial quick industrial paper or similar materials which require only seconds for developing can be used as the photosensitive recording paper 8 which means that photo-records are obtained rapidly, and economically. The means for supplying and moving the photosensitive recording paper 8 (not shown in FIG. 1) can be any conventional means, for example a drum and rollers, and the paper 8 is moved past the photo-fibre plate 7a at a suitable constant speed for receiving an impression (e.g. ZOcm/s); after the paper 8 has been exposed to the memory tube 7 electron beam, which corresponds to the image scanned by the camera tube 6, it is transported to a developing unit (not shown in FIG. 1), where the images received are immediately developed. In addition, the feeding speed of the photosensitive recording paper is preferably synchronized with the sweep of the electron beam of the memory tube by means of a conventional control circuit (not shown in FIG. 1) in a known manner. All the abovedescribed items of elements in the apparatus of the present invention are conventional, including the X-ray generator 4, image multiplier tube 5, camera tube 6, photo-fibre memory tube 7, photosensitive recording paper 8, and the deflection circuit 13, and thus the production of the apparatus presents no technical difiiculties.

To simplify the explanation, it is assumed that there is shown in FIG. 1 an object to be inspected, which is for example a weld 1 joining two pieces of metal 2,3 being held at a certain suitable position on a floor in a known manner. On one side of the weld 1 there is positioned an X-ray generator 4, that is a source of electrons to strike the weld 1 and produces X-ray radiation, and on the other side of the weld 1 there is positioned an image multiplier tube 5 which receives X-ray radiation from the weld l and produces a corresponding image on a fluorescent screen 5a. The image formed on the fluorescent screen 5a is constantly scanned by a television camera 6 which carries out repeated scanning over the line of the fluorescent screen 5a. In response to the fluorescent screen 5a image scanned, the television produces video signals which are supplied to a photo-fibre memory tube 7. Scanning by the photofibre memory tube 7 is synchronized with that of the television camera 6 and its output is supplied through a face-plate 7a to a photosensitive recording paper 8; synchronization of television camera 6 and photo-fibre memory tube 7 are by any suitable conventional means,

comprising, for example, a common clock pulse emitter and a deflection circuits. The photosensitive recording paper 8 is moved past and in close contact with the photo-fibre memory face-plate 7a and thus there is imparted to the recording paper 8 a photo-image corresponding to the image scanned by the television camera 6, which is itself produced by X-rays from the weld 1, in other words there is a direct print'out on the recording material 8 of a radiograph of the weld 1. According to the invention there is also provided a wheeled platform 10, as shown in FIG. 2. The platform 10 has a flat top 10a, which has two legs 10b, to the lower part of which are attached wheels 9. On one side, the platform top 10a extends over and beyond one leg 10b and wheel 9, and extending downwards at right-angles to this side there is a side portion 100, which extends to substantially below the leg 10b and wheel 9', in other words, the side portion is formed outwards with respect to one leg 10b and wheel 9, i.e., further from the centre of the platform top 100, and on the opposite side of the platform top 10a to the other leg 10a and wheel 9, and the bottom of the side portion 100 is substantially below the lowest level of the wheels 9. A support shelf 10d extends inwards, i.e., towards the centre of the platform top 10a from the bottom of the side portion 10c; the final configuration of the platform 10 is therefore that the support shelf 10d lies parallel to the platform top 100, well below the platform 10a, legs 10b and wheels 9, and with the end of the support shelf 10d approximately below the centre of the platform top 10a, the cross-section of platform 10 thus roughly forming a rectangle from which a lower corner has been removed, so that it is partly open at one side. The X-ray generator 4 is mounted on and near the end of the support shelf 10d and an assembly 11 comprising the image multiplier tube 5 and television camera 6 is mounted on the platform top 10a and directly above the X-ray generator 4. The platform 10 is slid on to the welded pieces of metal 2,3 so that one wheel 9 rests on the piece of metal 3 and the other wheel 9 rests on the piece of metal 2, and the weld 1 lies between the X-ray generator 4 and the assembly 11. Transmission between the camera tube 6 and the photo-fibre memory tube 7 can be connected by cable or wireless disregarding of the distance between the both. Acting through the fibre-plate of the photo-fibre memory tube 7, the video signals received at the photo-fibre memory tube 7 produces a striated photo-image on the photosensitive recording paper 8. The paper 8 is moved past the end of the photo-fibre memory tube 7 and therefore successive photo-images of successive portions of the weld 1 passing the location being scanned by the camera tube 6, that is production of the X-ray generator 4 and the image multiplier tube 5, are imparted to suecessive portions of the paper 8 at the direction opposite to the moving direction of the paper 8, which thus pro-' vides a complete record of the weld 1 at the end of the movement of the wheeled platform 10. Accordingly, the photosensitive recording paper 8 developed makes it now possible to obtain a direct print-out of a radiograph of the weld 1 by actuating the X-ray generator 4 and assembly 11 and supplying the video signals from the television camera 6 to a photo-fibre memory tube 7 which imparts a corresponding image to a photosensitive recording paper 8. If now the length of the weld 1 is such that one radiographic exposure is insufficient for complete inspection thereof, it is merely necessary to move the platform 10 along the length of the weld 1 to obtain print-out of one continuous radiograph of the entire weld l on the photosensitive recording material being moved at a constant speed past the face-plate 7a of the photo-fibre memory tube 7. It is of course possible for the assembly 11 mounted on the platform top 10a to comprise not only the image multiplier tube 5 and television camera 6 but also the photo-fibre memory tube 7 and recording paper 8. Also, identification of radiographs of different welds is easily obtainable by providing each weld with a lead identification mark prior to radiographic examination. It will be understood that the apparatus of the. invention is not limited to the application described above but can be used for all forms of radiographic examination, for example, of human beings.

Also various changes or adaptations of the abovedescribed equipment are possible without in any way departing from the principles of the invention. For example, instead of moving recording material past a stationary photo-fibre memory tube, it is possible to move the photo-fibre memory tube past stationary recording material, or to move both memory tube and recording material relative to one another; the memory tube employed need not necessarily be a photo-fibre memory tube, but can be an electrostatic memory tube, thinwall memory tube, or any other suitable form of a cathode-ray tube adapted for transfer of information onto a recording material in response to electrical signals received. The recording material itself can be any suitable quick-developing recording material, not only quick industrial paper, but also, for example, diazo or electrostatic recording material or similar materials. Also the form of radiation employed for radiographic examination by the apparatus of the invention can be gamma rays as well as X-rays.

As is clear from the above description the apparatus of the invention makes it possible to obtain instantaneous photo-images of objects to be inspected by operation which can be fully automatic, or which can be provided with various manual controls for adjustments as considered convenient by those responsible for the inspection of objects. Also, transmission from the image receiving means to the image recording means is electrical, and therefore operation is faster and the elements of the apparatus can be separate from one another and in any convenient location. Also, the apparatus of the invention does not require any special circuitry or equipment, but uses only elements that are commercially available, and can simply and cheaply replace a conventional apparatus as a means for obtain- 5 ing photo-records in a short time. Thus it may be seen that the present invention provides an equipment that is simple in construction and operation and has the advantages over conventional equipment that radiographs are obtained more quickly and more cheaply, and that single continuous radiograph of any length can be obtained. I

Although the present invention has been fully described, it is to be noted that various changes and modifications are apparent to those skilled in the art. Therefore, unless otherwise they departs from the true scope of the present invention, they should be construed as included within said scope of the present invention.

What is claimed is:

1. A radiograph recording apparatus for obtaining a continuous series of radiographs produced on the surface of a photosensitive recording paper comprising:

an X-ray generator means for generating X-rays toward an object to be examined,

an image multiplier tube which produces an image on a fluorescent screen of said image-multiplier tube in response to said X-rays received from said object,

a platform structure including an upper platform portion supporting said X-ray generator means and a lower platform portion supporting at least said image multiplier tube, said upper and lower platform portions being connected in said platform structure with a cross-section which is approximately rectangular, said object being placed between said upper and lower platform portions, wherein said platform structure includes wheels for providing relative movement between said object and said X-ray generator and image multiplier tube,

a television camera tube means being arranged in connection with the image multiplier tube in such a manner that saidtelevisioncamera tube means continuously scans a line on said fluorescent screen of saidimage multiplier tube, said line scanbeing in the direction perpendicular to the direction of relative movement between said object and said X-ray generator and image multiplier tube,

an image reproducing means for converting a video signal from said television camera tube into image reproducing signals which scan linearly on a front plate of said image reproducing means, and

a photosensitive recording material which is moved in a direction parallel to the linear scan image reproducing signals of said image reproducing means.

2. A continuous radiograph recording apparatus comprising:

X-ray generator means for generating X-rays from an object to be examined,

an image multiplier means for producing a fluorescent screen image in response to said X-rays received from said object, said object being relatively movable with respect to said X-ray generator means, said video line scan being perpendicular to the direction of relative movement between said object and both said X-ray generating means and said image multiplier means,

an image reproducing means for converting said video signal into image reproducing signals which scan linearly on a front plate of said image reproducing means, and

photosensitive recording means for recording said linear scan of said image reproducing means, said photosensitive recording means being moved in a direction parallel to said linear scan of said image reproducing means.

3. A continuous radiograph recording apparatus according to claim 2, wherein said X-ray generator means and said image multiplier means are supported on a movable platform means. 7

4. A continuous radiograph recording apparatus according to claim 3, wherein said movable platform means support said image multiplier means and said X-ray generator means in spaced alignment with respect to one another, said object being arranged apart from said platform means between said X-ray generator means and said image multiplier means.

5. A continuous radiograph recording apparatus according to claim 2, wherein deflection circuit means are provided for controlling the width of said video line scan produced by said television camera means.

6. A continuous radiograph recording apparatus according to claim 5, wherein said deflection circuit means simultaneously controls said image reproducing signal line scan of said image reproducing means in synchronization, with said video line scan.

7. A continuous radiograph recording apparatus according to claim 2, wherein said image reproducing means include a photo-fibre memory tube.

8. A continuous radiograph recording apparatus according to claim 2, wherein said video signals from said teevision television means are electrically transmitted to said image reproducing means.

UNITED STATES 'PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 855,471 Dated December 17,1974

Inventor (s) YOShiZO IKEGA MI It is certified that error appears in the above-identified patent and that said Letters Patent are hereby'corrected as shown below:

Title page, insert the following:

[30] Foreign Application Priority Data April 24, 1972 Japan o 4156 3/1972 Signed and sealed this 1st day of April 1975.

(SEAL) Attest:

C. I-[ARSHALL DAMN ZEUTIZ'C. T-ZASOTI Commissioner of Patents -ettesting Officer and Trademarks F ORM PO-I 050 (10-69) USCOMMDC 60376-P69 9 U S. GOVERNMENY FRINYING OFFICE: 1959 0-365-334 

1. A radiograph recording apparatus for obtaining a continuous series of radiographs produced on the surface of a photosensitive recording paper comprising: an X-ray generator means for generating X-rays toward an object to be examined, an image multiplier tube which produces an image on a fluorescent screen of said image multiplier tube in response to said X-rays received from said object, a platform structure including an upper platform portion supporting said X-ray generator means and a lower platform portion supporting at least said image multiplier tube, said upper and lower platform portions being connected in said platform structure with a cross-section which is approximately rectangular, said object being placed between said upper and lower platform portions, wherein said platform structure includes wheels for providing relative movement between said object and said X-ray generator and image multiplier tube, a television camera tube means being arranged in connection with the image multiplier tube in such a manner that said television camera tube means continuously scans a line on said fluorescent screen of said image multiplier tube, said line scan being in the direction perpendicular to the direction of relative movement between said object and said X-ray generator and image multiplier tube, an image reproducing means for converting a video signal from said television camera tube into image reproducing signals which scan linearly on a front plate of said image reproducing means, and a photosensitive recording material which is moved in a direction parallel to the linear scan image reproducing signals of said image reproducing means.
 2. A continuous radiograph recording apparatus comprising: X-ray generator means for generating X-rays from an object to be examined, an image multiplier means for producing a fluorescent screen image in response to said X-rays received from said object, said object being relatively movable with respect to said X-ray generator means and image multiplier means, a television camera means for producing a video signal in response to a continuous line scan of said fluorescent screen image by said television camera means, said video line scan being perpendicular to the direction of relative movement between said object and both said X-ray generating means and said image multiplier means, an image reproducing means for converting said video signal into image reproducing signals which scan linearly on a front plate of said image reproducing means, and photosensitive recording means for recording said linear scan of said image reproducing means, said photosensitive recording means being moved in a direction parallel to said linear scan of said image reproducing means.
 3. A continuous radiograph recording apparatus according to claim 2, wherein said X-ray generator means and said image multiplier means are supported on a movable platform means.
 4. A continuous radiograph recording apparatus according to claim 3, wherein said movable platform means support said image multiplier means and said X-ray generator means in spaced alignment with respect to one another, said object being arranged apart from said platform means between said X-ray generator means and said image multiplier means.
 5. A continuous radiograph recording apparatus according to claim 2, wherein deflection circuit means are provided for controlling the width of said video line scan pRoduced by said television camera means.
 6. A continuous radiograph recording apparatus according to claim 5, wherein said deflection circuit means simultaneously controls sai image reproducing signal line scan of said image reproducing means in synchronization, with said video line scan.
 7. A continuous radiograph recording apparatus according to claim 2, wherein said image reproducing means include a photo-fibre memory tube.
 8. A continuous radiograph recording apparatus according to claim 2, wherein said video signals from said teevision television means are electrically transmitted to said image reproducing means. 